Contrast induced nephropathy is a rare condition in which kidney function is reduced after exposure to certain contrast dyes. In most cases, it resolves on its own in a week or two.

Chemicals known as contrast dyes are used in approximately 25% of MRI exams as well as other imaging tests, like CT scans, and certain cardiology procedures. Injected into the body, these compounds enhance the image quality to give medical professionals a better picture of what’s happening in your body.

However, like with any procedure, risks are possible. There is a slight chance the contrast dye can cause kidney damage.

While this condition is rare and frequently resolves on its own, its risks should still be assessed before undergoing any procedure that uses contrast dyes.

Contrast induced nephropathy is a rare condition in which exposure to the contrast dyes used in certain medical tests hurts kidney function.

While there’s some debate over the exact criteria for contrast induced nephropathy, doctors frequently look for either of the following effects:

While decreased kidney function usually appears within 48 to 72 hours, impaired renal function that happens within 7 days of a contrast procedure and that can’t be attributed to another possible cause may also be classified as contrast induced nephropathy.

About 2% of people receiving dyes develop contrast induced nephropathy.

However, some conditions and factors can increase the likelihood of experiencing contrast induced nephropathy, including:

According to the National Kidney Foundation, the percentage of people who experience contrast induced nephropathy can increase 30% to 40% in people with advanced kidney disease. There’s also a 20% to 50% higher chance for people with both chronic kidney disease and diabetes.

Symptoms of contrast induced nephropathy can be similar to those of kidney disease. They may include:

  • feeling tired
  • reduced appetite
  • swelling in the feet and ankles
  • puffiness around the eyes
  • dry or itchy skin

Different types of nephropathy

“Nephropathy” is a medical term for deteriorating kidney function. Some forms of nephropathy, like IgA nephropathy, can develop slowly over time, but contrast induced nephropathy typically reveals itself within just 2 to 3 days of the procedure.

Additionally, while some types of nephropathy, like diabetes-related nephropathy, require treatment of an underlying condition and may require various medications, contrast induced nephropathy frequently resolves on its own in a week or two.

The best way to prevent contrast induced nephropathy is to understand the risk factors ahead of the medical procedure where you might be exposed to the contrast dyes.

Before a medical scan that includes contrast, let your doctor know about any risk factors for contrast induced nephropathy you may have. You can also discuss if there are any alternative tests besides a procedure with contrast that might be appropriate.

Follow any care instructions given before, during, and after the procedure with contrast, like drinking plenty of liquids to stay hydrated and help remove the contrast from the body.

If symptoms of contrast induced nephropathy appear after the procedure, let your doctor know right away.

Medical professionals should consider the risks of contrast induced nephropathy before the imaging test is done.

If medical professionals determine that the benefits of the contrast procedure outweigh the risks, they may prescribe saline, sodium bicarbonate, or both intravenously 6 to 12 hours before the procedure for people with chronic kidney disease to help prevent contrast induced nephropathy.

For others, medical professionals typically advise you to drink plenty of water in the first hours after the MRI or CT scan to flush the contrast dyes from your system.

In most cases, contrast induced nephropathy is a self-resolving issue.

About 7 to 14 days after being exposed to the contrast, renal function typically returns to normal. Fewer than one-third of people with contrast induced nephropathy have residual renal issues.

Less than 1% of people require renal replacement therapy.

However, if someone has diabetes and severe kidney failure, they may need dialysis.

Contrast induced nephropathy is a rare condition that can occur after contrast is used during medical imaging. In most cases, kidney function returns to normal within a week or two without intervention.

If your doctor suggests medical imaging with contrast dyes, let them know about any risk factors for contrast induced nephropathy you may have, like diabetes or kidney disease. In some cases, alternative procedures without contrast dyes may be available.